I'm looking at upgrading my 4L60e and at the same time going to vacuum modulation. Anyone know the impacts of vacuum modulation if one were to add a s/c in the future? I know there is a relation between the two and that a bypass is required if you have both Vacuum Modulation and a Supercharger (FI), but I don't know how that works.

If I were planning to add a blower in the future, would I install the bypass now, or then?
Would it be unwise to have the bypass installed BEFORE you had a blower installed (i.e. you are planning to install a blower in the next year or so)?
Is it something that can easily be added two years down the road?

If anyone knows much about this, I'd apprecaite some clarification.

 

you gotta have a bypass valve...add it when you add your charger/turbo...till then just run without it...reallly easy to install...hope this helps ...Dave

 

Thanks Rock On. Makes sense.

What does it really do though?

 

Mine has a check valve in the vacuum line to prevent boost from damaging the vacuum modulator.

 

Where can you get this check valve at? I will be needing one soon i hope.

 

Transgo has a check valve kit that you can add to their vacuum modulated shift kit.Chuck at FLP adds it to his transmissions that will be used for boosted applications.

 

Thx for the explanations. Clears that up for me.